This invention relates to a method and device for effectively treating dysphagia. In particular, the present invention relates to a method and device for treating dysphagia by providing electrical stimulation to the pharyngeal region of an associated animal.
Dysphagia is the inability to swallow or difficulty in swallowing and may be caused by stroke, neurodegenerative diseases, or respiratory disorders. Swallowing is a complicated action which is usually initiated voluntarily but always completed reflexively, whereby food is moved from the mouth through the pharynx and esophagus to the stomach. The act of swallowing occurs in three stages and requires the integrated action of the respiratory center and motor functions of multiple cranial nerves, and the coordination of the autonomic system within the esophagus.
In the first stage, food is placed on the surface of the tongue. The tip of the tongue is placed against the hard palate. Elevation of the larynx and backward movement of the tongue forces the food through the isthmus of the fauces in the pharynx. In the second stage, the food passes through the pharynx. This involves constriction of the walls of the pharynx, backward bending of the epiglottis, and an upward and forward movement of the larynx and trachea. Food is kept from entering the nasal cavity by elevation of the soft palate and from entering the larynx by closure of the glottis and backward inclination of the epiglottis. During this stage, respiratory movements are inhibited by reflex. In the third stage, food moves down the esophagus and into the stomach. This movement is accomplished by momentum from the second stage, peristaltic contractions, and gravity. Although the main function of swallowing is the propulsion of food from the mouth into the stomach, swallowing also serves as a protective reflex for the upper respiratory tract by removing particles trapped in the nasopharyrix and oropharynx, returning materials refluxed from the stomach into the pharynx, or removing particles propelled from the upper respiratory tract into the pharynx. Therefore, the absence of adequate swallowing reflex greatly increases the chance of pulmonary aspiration.
In the past, patients suffering from dysphagia have undergone dietary changes or thermal stimulation treatment to regain adequate swallowing reflexes. Thermal stimulation involves immersing a mirror or probe in ice or cold substance. The tonsillar fossa is stimulated with the mirror or probe and the patient closes his mouth and attempts to swallow. While these traditional methods are usually effective for treating dysphagia, these methods often require that the patient endure weeks or months of therapy.
Electrical stimulation has often been used as a method for alleviating pain, stimulating nerves, and as a means for diagnosing disorders of the spinal cord or peripheral nervous system. Electrical stimulation has further been used to facilitate muscle reeducation and with other physical therapy treatments. In the past, electrical stimulation was not recommended for use in the neck or thoracic region as severe spasms of the laryngeal and pharyngeal muscles may occur resulting in closure of the airway or difficulty in breathing. Further, the introduction of electrical current into the heart may cause cardiac arrhythmia. Electrical stimulation has been used to stimulate the recurrent laryngeal nerve to stimulate the laryngeal muscles to control the opening of the vocal cords to overcome vocal cord paralysis, to assist with the assessment of vocal cord function, to aid with intubation, and other related uses. However, heretofore, electrical stimulation has not been used in the treatment of dysphagia to promote the swallowing reflex which involves the integrated action of the respiratory center and motor functions of multiple cranial nerves, and the coordination of the autonomic system within the esophagus.
It is desirable to have a simple, non-invasive method and device for treating dysphagia and artificially promoting swallowing.